Quinceañero is a commonly used masculine form for a boy celebrating his 15th birthday.
The word follows Spanish gender patterns, changing the final -a of quinceañera to -o. It is used for related celebrations sometimes called a quinceañero or quince años celebration for boys.
Traditional quinceañera customs have historically focused on girls, but families and communities have adapted the milestone in different ways. A boy’s celebration may borrow formal clothing, dancing, family ceremonies, or other elements associated with quinceañeras.
Usage is not identical across Spanish-speaking regions. The masculine term is therefore best understood as a recognized related form, not evidence that every community follows one universal ceremony.